Sato Kohei, Sadamoto Tomoko, Ueda-Sasahara Chihoko, Shibuya Kenichi, Shimizu-Okuyama Shizuyo, Osada Takuya, Kamo Mifuyu, Saito Mitsuru, Kagaya Atsuko
Research Institute of Physical Fitness, Japan Women's College of Physical Education, Kita-Karasuyama, Setagaya-ku, Tokyo, 157-8565, Japan.
Exp Physiol. 2009 Nov;94(11):1132-8. doi: 10.1113/expphysiol.2009.048595. Epub 2009 Jul 31.
We examined the role of central command in static exercise-induced increase in middle cerebral artery mean blood flow velocity (V(MCA)). Eleven young female subjects performed static elbow flexion for 2 min at 30% maximal voluntary contraction without (control exercise; CONT) and with vibrations to the biceps brachii tendon (EX+VIB) in order to reduce the effort needed to maintain the set contraction intensity. The rating of perceived exertion in exercising muscle (Arm RPE) at the end of EX+VIB was lower than that of CONT (mean +/- s.d.; 4.8 +/- 1.1 for CONT versus 3.5 +/- 1.0 for EX+VIB; P < 0.05). The increases in mean arterial pressure (36 +/- 8 versus 22 +/- 7%; P < 0.05), heart rate (36 +/- 16 versus 21 +/- 7%; P < 0.05) and cardiac output (56 +/- 26 versus 39 +/- 14%; P < 0.05) during EX+VIB were also lower than those during CONT. Similarly, the increase in the V(MCA) during EX+VIB was lower than that during CONT (29 +/- 5 versus 17 +/- 14%; P < 0.05). These results suggest that the influence of central command contributes to cerebral blood flow regulation during static exercise and the decrease in V(MCA) is likely to be caused by attenuated brain activation in the central command network and/or by the reduction in cardiac output.
我们研究了中枢指令在静态运动引起的大脑中动脉平均血流速度（V(MCA)）增加中的作用。11名年轻女性受试者在30%最大自主收缩强度下进行2分钟的静态屈肘运动，分为无振动（对照运动；CONT）和肱二头肌肌腱振动（EX+VIB）两种情况，以减少维持设定收缩强度所需的努力。EX+VIB结束时运动肌肉的主观用力感觉评分（手臂RPE）低于CONT（平均值±标准差；CONT为4.8±1.1，EX+VIB为3.5±1.0；P<0.05）。EX+VIB期间平均动脉压（36±8%对22±7%；P<0.05）、心率（36±16%对21±7%；P<0.05）和心输出量（56±26%对39±14%；P<0.05）的增加也低于CONT期间。同样，EX+VIB期间V(MCA)的增加低于CONT期间（29±5%对17±14%；P<0.05）。这些结果表明，中枢指令的影响有助于静态运动期间的脑血流调节，V(MCA)的降低可能是由中枢指令网络中大脑激活减弱和/或心输出量减少引起的。
